sigmaplot
Plot singular values of frequency response and return plot handle
Syntax
h = sigmaplot(sys)
sigmaplot(sys,{wmin,wmax})
sigmaplot(sys,w)
sigmaplot(sys,w,TYPE)
sigmaplot(AX,...)
sigmaplot(..., plotoptions)
Description
h = sigmaplot(sys) produces a singular
value (SV) plot of the frequency response of the dynamic
system sys. It also returns the plot handle h.
You can use this handle to customize the plot with the getoptions and setoptions commands.
Type
help sigmaoptions
for a list of available plot options.
The frequency range and number of points are chosen automatically.
See bode for details on the
notion of frequency in discrete time.
sigmaplot(sys,{wmin,wmax}) draws the SV
plot for frequencies ranging between wmin and wmax (in rad/TimeUnit,
where TimeUnit is the time units of the input dynamic
system, specified in the TimeUnit property
of sys).
sigmaplot(sys,w) uses the user-supplied
vector w of frequencies, in rad/TimeUnit,
at which the frequency response is to be evaluated. See logspace to generate logarithmically
spaced frequency vectors.
sigmaplot(sys,w,TYPE) or sigmaplot(sys,[],TYPE) draws
the following modified SV plots depending on the value of TYPE:
| TYPE = 1 | --> | SV of inv(SYS) |
| TYPE = 2 | --> | SV of I + SYS |
| TYPE = 3 | --> | SV of I + inv(SYS) |
sys should be a square system when using
this syntax.
sigmaplot(AX,...) plots into the axes with
handle AX.
sigmaplot(..., plotoptions) plots the singular
values with the options specified in plotoptions.
Type
help sigmaoptions
for more details.
Examples
Singular Value Response Plot with Custom Plot Options
Plot the singular value responses of a dynamic system.
sys = rss(3,3,5); h = sigmaplot(sys);
Set properties of the plot handle h to customize the plot. For example, change the plot units to Hz.
setoptions(h,'FreqUnits','Hz');
Tips
You can change the properties of your plot, for example the units. For information on the ways to change properties of your plots, see Ways to Customize Plots.